Frequently asked questions in orthopedics

Those who frequent the Internet will be familiar with the concept of “FAQ’s” or “frequently asked questions” that can be found on most Web sites. A great many of the orthopedic-related questions I receive from colleagues touch on common themes such that a set of “FAQ’s” might be of help.

I’ve got a 5-year-old dog with dysplastic hips that has developed an acute hind limb lameness. I’m concerned that he seems to have a cruciate rupture, but what should I do about his hips?

Probably nothing! It sounds like this dog hasn’t been bothered by his hips previously, and, indeed, that is the case with more than 75% of dysplastic dogs (1,2). An acute cruciate rupture is undoubtedly the cause of the lameness; dealing with that will likely resolve the lameness. A recent survey showed that 60% of dogs presented to a referral center for evaluation and treatment of “hip” problems were actually lame due to cruciate disease (3).

A dog has been hit by a car and sustained some pelvic fractures. How do I decide whether he’s a surgical candidate or whether cage rest and analgesia will be sufficient?

Several factors go into making this decision. From a medical standpoint, surgery is preferred if there is disruption of the vertebral/sacrum/ilium/coxofemoral joint weight-bearing axis. Surgery is also preferred to avoid future constipation problems if pelvic fractures produce more than 25% narrowing of the pelvic canal. Involvement of the acetabulum, neuropraxia, or intractable pain are also indications for surgery (4,5). The presence of additional orthopedic injuries, for example a contralateral long bone fracture, might make pelvic fracture repair an attractive option for helping the patient to be ambulatory much sooner. Patient size may also enter into the decision. Larger dogs, especially if obese, may have a much greater challenge in getting around without surgical stabilization. Finally, financial considerations inevitably enter into this decision. Surgical repair, especially of multiple injuries, can be cost-prohibitive for some owners. All this being said, nearly all pelvic fractures will heal with conservative therapy. The degree of malunion that might result and the long-term consequences, however, can be difficult to predict.

I’ve got a dog with fractures of the 2nd and 3rd metacarpals (metatarsals). He needs surgery, right?

Not necessarily. Classic dogma in veterinary and human orthopedics has been that more than 1 fractured metacarpal or metatarsal, especially if it is of the major weight-bearing bones (#3 and #4), articular fractures, or displaced fractures are indications for surgery. Retrospective outcome analysis in dogs, cats, and humans has shown that these recommendations may not hold water (6,7). Results of external coaptation of these fractures were at least as good as surgical repair; however, these fractures are notoriously slow-healing. Radiographs taken at 4–6 wk post-injury commonly show remarkably little evidence of healing; most will go on to union by 12 wk. The other potential concern can be in toy breeds. Just as with distal radius/ulna fractures, small breeds are plagued with poor blood supply to the healing fracture and a higher incidence of nonunion is expected.

A 4-year-old poodle with bilateral medially luxating patellas has been acutely lame in the right hind for the last week. Should I fix the patellar luxation? In both stifles? At the same time? With what techniques?

It is unlikely that the patellar luxation is a significant contributor to the dog’s lameness since the problem has been present for most of the dog’s life and the symptoms are described as being acute. A cruciate rupture is the most likely problem on the list of differential diagnoses. If one were to address a cruciate rupture surgically in such a dog, the question would then be whether or not to also address the patellar luxation at the same time. On this question opinions vary; some would say that combinations of tibial tuberosity transposition, recession sulcoplasty, and soft tissue corrections are logical procedures to perform while stabilizing the cruciate rupture. Others, including the author, would take the approach that if the dog was not bothered by the patellar luxation before rupturing his cruciate then there is no need to “fix what ain’t broke.” The extracapsular suture placed to stabilize the cruciate-deficient stifle also provides some stabilization to many luxating patellas.

If the question pertained to an 8-month-old small breed pup with bilateral clinical signs attributable to patellar luxation, then bilateral corrective surgery at the same session is a very viable option. Published reports suggest that tibial tuberosity transposition is the technique most closely associated with surgical success, especially in grade 3 or 4 luxations (8). Most grade 3 and 4 luxations that do not undergo tibial tuberosity transposition will reluxate (8).

I have a client with limited finances who cannot afford surgery on his dog’s femoral fracture. Is there some sort of splint or cast I can put on this?

No. The trouble is that some problems just don’t have a plan B, C or D. The overwhelming majority of fractures, especially of the femur and humerus, fall into this category. Placing a bandage or splint on these fractures cannot provide adequate stability and is much more likely to act as a weight on the end of the limb displacing the fracture further (9).

I’m starting to do extracapsular cruciate repairs and I have difficulty visualizing the menisci. Do you have any tips? Do I really have to examine the meniscus?

Welcome to the club! Visualizing and dealing with meniscal pathology is the most challenging part of surgically treating cruciate disease…and many would say the most important part. The most common reason for post-operative lameness that doesn’t resolve relates to meniscal tears; some that develop after surgery, but others that are missed at surgery. There are many techniques for visualizing the menisci during stifle arthrotomy. Most commonly these involve retraction of the patella in a luxated position with a Gelpi retractor. Forward subluxation of the cranial tibia can be accomplished with a Senn retractor hooked in the intermeniscal ligament or by the placement of the tip of a 6-mm Hohmann retractor behind the caudal tibial plateau while levering against the trochlear groove of the distal femur. The tip of the Hohmann retractor is placed just medial to the insertion of the caudal cruciate ligament to protect the ligament and to effectively lever the tibia. Finally, the femur and tibia can be pried apart for improved visualization with the use of a stifle distractor or a small Gelpi retractor where the points are inserted at the intercondylar notch of the femur and at the cranial cruciate insertion on the tibia (10,11).